Introduction of and desire for IP-based communications systems and services motivate telecommunication operators to migrate customers (subscribers) and services from a conventional telecommunications network (a donating network), e.g. circuit switched and/or soft switch based network to a new IMS-based next generation network (NGN) (the receiving network). Such IMS-based NGNs include communications networks based on the 3GGP IMS architecture which provides an all-IP platform for delivery of video, voice and multimedia services.
IMS-based NGNs are generally characterized by a control layer comprising serving network node(s) for handling session control, an application layer associated with application servers for executing services and a transport layer associated with a multi-service IP network for handling the underlying data transport.
A further need for service migration stems from consolidation between existing IMS-based NGN networks wherein service migration from an IMS-based donating network to a new IMS-based receiving network is required. Meanwhile, services associated with new (non-migrating) subscribers to the new (receiving) IMS-based network may require service activation which support number portability and other related portability services. Such may be the case when an operator operating an IMS-based receiving network accepts a new subscriber, which used to be subscribed to for instance an IMS-based, or otherwise SIP-based network operated by another competing operator, wherein the subscriber wishes to retain its number.
In order to migrate a service from a donating to a receiving network, at least the receiving network needs to be reconfigured such that it is able to deliver the requested one or more services to the (migrated) subscriber via its platform. Consequently, in a migration scenario, the delivery of the original service to the (migrated) subscriber by the donating network is disabled and the new service in the receiving network is activated. In order to keep the Quality of Services high, it is a desire of operators of receiving networks that such a migration should be without or almost without service interruptions. This is further stimulated by governmental regulations requiring minimal service interruption during the migration process.
Also in situations wherein a user activates a service associated with a newly acquired client, portability issues may have to be resolved during the activation. The operator however has no knowledge in advance when a subscriber activates the new client. In some cases a happy call by the subscriber is required to indicate to the operator of the receiving network that the client for accessing the receiving network is ready (configured) for use. It is then up to the operator to efficiently process the happy call and make the necessary arrangements in the receiving network. In migration scenario's, in most cases configuring the client for accessing the receiving network, automatically causes the disablement of the use of services via the donating network. It is clear that a poorly timed service activation or service migration may thus result in service interruptions leading to undesired situations where the user is not reachable and/or cannot transmit outgoing data.
Hence, there is a need in the art for improved methods and systems for service migration and/or activation. In particular, there is a need in the art for methods and systems for allowing efficient service migration to a next generation network, which allows multiple services to be migrated and/or activated while minimizing the chance of undesired service interruptions.